Complete analyses of reptiles from Iowa, Arizona, and Texas for organochlorine insecticide residues. Study various parameters of adsorption and desorption of insecticides with soil. Study the metabolism of selected organophosphorus and carbamate insecticides by perfusing them through intact, viable, procine livers. BIBLIOGRAPHIC REFERENCES: Franson, J.C., P.A. Dahm, and L.D. Wing. A method of preparing and sectoning mink (Mustela vison) mandibles for age determination. The Amer. Midland Naturalist 93: 507-508. 1975. Sellers, L.G. and P.A. Dahm. Chlorinated hydrocarbon residues in ground beetles (Harpalus pensylvanicus) and Iowa soil. Bull. Environ. Contam. Toxicol. 13: 218-222. 1975.